Snap one (active) vertex in a selected curve + move all vertices in curve by snap amount?
In this example, 'Snap With' is set to 'Active' and 'Snap To' is set to 'Vertex'.
The snap has been set to 'Project onto Self', and set to work in translation, rotation, and scale.
The Pivot has been set to '3D Cursor'.. although of course, that wouldn't matter if you were just translating..

In the illustration, the active vertex starts off as the one at the bottom, and is then switched to the one at the other end.
When you move, rotate, (or scale) the active vertex, the other selected vertices will follow.
Note: the rotation has to be constrained to an axis to work.